This invention relates generally to marine equipment and, more particularly, to an apparatus and method for locating objects under a body of water.
Various types of apparatus for conducting dredging operations and removing sediment material from under a body of water are known in the art. Although such apparatus may conduct dredging operations relatively reliably, such apparatus are susceptible to damage from objects or undesirable items present at the floor surface of the body of water. Furthermore, depending upon the depth of the sediment removal operation being conducted, such apparatus are also susceptible to damage from objects buried in the sediment material beneath the floor surface. In order to prevent such damage, it is desirable to determine and locate the presence of such objects prior to conducting a dredging operation such that the dredging apparatus may be either maneuvered around or over such objects during operation thereof, or such objects may be retrieved and removed altogether prior to conducting the dredging operation.
There are some devices that are designed and constructed for locating objects under a body of water such as those devices that normally utilize some type of radar apparatus to locate objects under the body of water. Typically, such radar apparatus is attached to a towline and dragged along the floor surface of the body of water via a boat. In this situation, any sensor such as a global positioning system (GPS) sensor to identify the position of the object relative to the towed radar device would have to be located on the boat and a complex and expensive sonar system would be necessary to accurately determine the Cartesian (x, y and z) coordinates of the object. Furthermore, the weight of the radar apparatus usually causes such device to penetrate at least partially into the relatively soft and loose sediment material typically present at the floor surface of the particular body of water whereby the functioning of the device may be adversely impacted and/or the apparatus may be damaged from being dragged through the sediment material.
It is therefore desirable to provide an apparatus which can accurately locate objects under a body of water without utilizing complex and expensive sonar equipment to accurately determine the Cartesian (x, y and z) coordinates of such objects and which apparatus is unlikely to significantly penetrate the floor surface of the body of water during use.
Accordingly, the present invention is directed to overcoming one or more of the problems as set forth above.
In one aspect of the present invention, a apparatus adapted for locating objects under a body of water is disclosed. The apparatus includes a frame structure, at least one sensor assembly connected to the frame structure, wherein the sensor assembly includes a geographic location system receiver, such as a global positioning system (GPS) and an object detection device, such as ground penetrating radar. The geographic location system receiver being spaced a known distance from the object detection device, the object detection device being operable to detect a density change indicative of an object under the body of water, the object detection device being further operable to emit a signal indicative of the detection of an object under the body of water relative thereto based density change sensed thereby, and the geographic location system receiver being operable to emit a signal indicative of the present position of the receiver.
In another aspect of this invention, a method for locating objects under a body of water is disclosed. The method includes the steps of positioning in a body of water an apparatus operable to locate objects under the body of water, the apparatus including a geographic location system receiver and an object detection device spaced at a known distance relative to each other, detecting an object by sensing a change in density indicative of an object under a body of water, emitting a signal from the object detection device based upon a sensed density change indicative of a location of an object relative to the object detection device, sensing a signal indicative of the present position of the receiver by the geographic location system receiver, and emitting a signal indicative of the present position of the receiver by the receiver.